This invention relates generally to apparatus and methods for packaging food products, and more specifically, to improved apparatus and methods for preparing partially filled food casings for loaf style meat and sausage products.
In the manufacture of meat and sausage products, it is customary to prepare, for example, a meat emulsion from comminuted meat together with fillers, seasonings, spices, etc. A tubular food casing, such as non-edible cellulose is loaded onto the stuffing horn of a filling machine and stuffed with the meat emulsion. For sausage products like bologna, salami, and the like, the meat emulsion is introduced into large, heavy walled type casings and formed into chubs or lengthy individual sausage sticks having a rounded configuration.
As alternatives to large round shaped meat and sausage products, various apparatus and methods have been proposed for preparing elongated rectangular shaped or loaf style sausage and meat products, e.g. ham loaf, turkey loaf, etc. One specific example relating to means for manufacturing loaf style products is disclosed by U.S. Pat. No. 4,434,528 to Niedecker. Niedecker's method begins with preparation of slack filled casing containing the desired final quantity of meat which is less than the casing's volumetric capacity. A first length of casing is initially filled to capacity with the desired final volume of emulsion. A partially closed clip is applied to the trailing end of the casing, but before being fully closed the filled portion of the casing is compressed between a pair of mechanical jaws to extrude a portion of the emulsion upstream towards the stuffing horn. The pressure simultaneously withdraws additional unfilled casing downstream in the filling direction causing the casing to be drawn through the partially closed clip to form a slack or partially filled casing.
While the methods of Niedecker may be capable of providing satisfactory slacked filled loaf shaped products, they are dependent on the direct application of substantial force by compression means for withdrawing additional casing through a partially closed clip. Unless the casing readily threads through this clip with pressure applied by the mechanical jaws there is an increased statistical risk of casing rupture occurring. This means potentially costly down time for cleanup, lost meat emulsion in the work area, lost production and wasted casings. The methods of Niedecker are also dependent on the separate step of reshaping the slack filled casing into square shaped products by placement into loaf shaped molds.
U.S. Pat. No. 4,980,949 to Thomas R. Stanley discloses an improved apparatus and method for preparing slack filled food casings which effectively reduces the potential risk for casing rupture. This is performed with the aid of a casing slacker system for withdrawing an additional length of unfilled casing from the stuffing horn after the leading end of the casing is filled with a foodstuff, followed by the application of an end closure clip to the trailing unfilled end of the partially filled casing. As a final step in the preparation of a shaped slack filled product Stanley suggests uniformly distributing the meat emulsion into the unfilled portion of the sealed casing manually by the machine operator working the partially filled casing by hand.
While the methods and apparatus of U.S. Pat. No. 4,980,949 offer significant improvements in the preparation of loaf style products the final steps of distributing the meat product throughout the casing and shaping the product manually are not entirely satisfactory. The process does not always result in a consistently uniformly sized product and because it is largely carried out by hand performing this function repeatedly may increase the potential for job related injuries occurring.
German Offenlegungsschrift 2 054 441 published May 10, 1972 describes an apparatus for forming shaped filled sausage casings wherein the casing is underfilled by metering the sausage meat into the casing. The apparatus requires careful metering control and does not redistribute sausage meat from a first filled portion of a casing to a second portion to obtain the desired underfilled condition. In order for the apparatus to properly function, the speed of movement of the casing must be carefully synchronized with extrusion of a metered quantity of sausage meat.
German Offenlegungsschrift 2 210 054 published Sep. 6, 1973 describes an apparatus for forming pairs of skinless sausages by squeezing a roll of sausage meat in a mold formed by a conveyor with side rims. Meat is squeezed to form the start of a pair but a casing is not underfilled and then molded nor is a first region of a casing filled followed by redistributing meat to a second region of the casing.
Accordingly, there is a need for more efficient apparatus and methods of distributing foodstuff in partially filled casings and for shaping into loaf style meat and sausage products without substantial risk of casing rupture and which largely eliminates manual shaping operations.